The present invention relates to an automated highway system for controlling the operation of cars travelling thereon. The goal of such highway systems is to provide improved traffic control and higher speed traffic flow.
Various technologies for the automated highway system have been proposed. These technologies include image processing, optical lasers, radar systems, rf detectors, acoustic sensors, and magnetic sensors. These systems and sensors were conceived as installed on automobiles and many of these sensors and detectors contain a high degree of complexity and sophistication. Such systems and sensors are shown, for example, in U.S. Pat. No. 4,962,457 to Chen et al teaching a transmitter installed on a vehicle, in U.S. Pat. No. 5,196,846 to Brokelsby et al teaching a vehicle identification system, and in U.S. Pat. No. 4,052,595 to Erdmann et al teaching an automatic vehicle monitoring system.
However, to maintain stability in close "platoon" formations it is necessary to employ inter-vehicle communications. Some systems, such as PATHs magnetic nails, are shown in U.S. Pat. No. 1,361,202 to Minavitel teaching an imbedded metallic guardrail, and in U.S. Pat. No. 5,126,941 to Gormu et al teaching a vehicle guidance system. Such PATHs magnetic nails take advantage of roadway vehicle cooperation to simplify the sensor requirements in controlling the vehicles. Others install radio equipment above the roadway to communicate with vehicles, such as shown in U.S. Pat. No. 5,128,669 to Dodds et al, which relates to communicating information by radio.
Other attempts are also known in the prior art. In U.S. Pat. No. 5,196,846 to Brockelsby, a road side interrogator and transponder is taught for moving vehicle identification. In U.S. Pat. No. 5,182,555 to Summer, a traffic congestion communication system is shown. U.S. Pat. No. 5,164,732 to Brockelsby teaches a roadway interrogator antenna system. U.S. Pat. No. 5,134,393 to Henson discloses roadway positioned detectors/processors. In U.S. Pat. No. 5,128,669 to Dadds, overlapping transponders are taught. U.S. Pat. No. 5,126,941 to Gurmu teaches guiding vehicles with roadside controls. U.S. Pat. No. 4,968,979 to Mizuno teaches buried roadway vehicle detection. U.S. Pat. No. 4,962,457 to Chen discloses roadway installed site specific information and communications. U.S. Pat. No. 4,789,941 to Nunberg teaches ultrasonic computerized vehicle classification. In U.S. Pat. No. 4,591,823 to Horvat, vehicle surveillance is taught. U.S. Pat. No. 4,361,202 to Minovitch teaches smart cars with roadway transponders. U.S. Pat. No. 4,350,970 to von Tomkewitsch teaches routing transmitters for roadway to vehicle transmission. U.S. Pat. No. 4,052,595 to Erdmann discloses transducers to vehicle monitoring. U.S. Pat. No. 4,023,017 to Ceseri discloses monitored roadways. Finally, U.S. Pat. No. 3,920,967 to Martin teaches a computerized roadway monitor at intersections.
Previously conceived automated highway system designs have been based on the above-discussed types of systems that contains sensors and processors that require communication between vehicles, or vehicles that are capable of acting alone. This approach has proven very complicated and expensive, and would require a relatively long time to develop.
It is therefore a problem in the art to reduce the necessary processing and the necessary position sensing from the vehicle, and to distribute it throughout the highway infra-structure.